Best L5P Delete Kit for 2017-2026 Duramax: What to Buy and Why

Two L5P Duramax setups can look almost identical in a product photo and still require a completely different tuning path once you start the job. Your model year, controller and the way the package is configured all affect whether everything will work together. Before you compare prices, run any setup you're considering through these six checks.

1. ECM coverage

This is the first thing to check. A delete pipe and EGR hardware won’t give you a complete setup if the factory ECM still needs the correct access and calibration path. On an L5P Duramax, the tuning side should be part of your buying decision from the start.

2. Exact model-year fitment

Don’t assume a pipe advertised for several years means the same tune works across all of them. The 2017-2023 trucks use the E41 ECM family, while 2024+ Duramax use E42, and the unlock workflow changes with the controller.

3. What’s included and what isn’t

Check for the programming hardware, tuning credits, CAN bus plugs where required, clamps, gaskets, muffler choice and optional TCM work. A lower headline price isn’t useful if you’re still missing half the parts needed to finish the Duramax truck.

4. Pipe material and build quality

For a Duramax truck that sees heat, moisture and winter roads, pipe material matters. T-409 stainless is a practical middle ground between cheaper aluminized steel and more expensive T-304 stainless. Also look at flange quality, welds and how the system mounts.

5. Tuning flexibility

Look at whether the package uses a single calibration, multiple power levels or SOTF. If you tow, a lower tow-oriented setting may matter more to you than the highest available horsepower file.

6. Fitment verification and support

For newer Duramax trucks especially, VIN verification can prevent an expensive mismatch. Your year, ECM, chassis and transmission all matter, and 2024-2026 trucks deserve an extra fitment check before the order goes out.

Use these six checks on any L5P setup you're considering, regardless of the price on the product page. They'll tell you whether the package actually matches your Duramax truck and whether you'll need anything else before the job starts.

We grouped the setups below by the kind of Duramax truck you're building, not by product name or pipe size. The goal is simple: find the configuration that matches how you actually use your truck, then compare the tuning path, included hardware and available options. The final price depends on the exhaust, muffler and optional TCM choices you select.

Best Overall for 2017-2023 - Full DPF/DEF/EGR Delete Kit with E41 ECM Tuning - From $3,227

Why to buy this one: If your L5P Duramax is a 2017 through 2023 model, this Full DPF/DEF/EGR Delete Kit with ECM Tuning gives you the mechanical hardware and the correct E41 tuning path in the same package. You select your model-year range when ordering, because the ECM access process isn't identical across all seven years.

For 2017-2019 trucks, the package includes the E41 Upgrade and Unlock Tool required for ECM access. Supported 2020-2023 Duramax use the HP Tuners programming interface without a separate ECM unlock device.[2] The custom calibration is prepared from your truck's VIN, ECM information, stock file and vehicle setup.

The available SOTF levels are Stock Optimized, +50, +75, +100 and +150 HP. You can also configure the hardware with a DPF Delete Pipe, 4-inch exhaust or 5-inch exhaust, with straight-pipe and muffled versions available.

Why it stands out

• One product covers 2017-2023 L5P pickups, with the ECM workflow matched to the selected model-year range.
• The package includes five SOTF levels: 0 / +50 / +75 / +100 / +150 HP.
• You choose the exhaust configuration during the order instead of buying a separate system later.
• TCM tuning is optional, so you only add it if your Duramax truck and the way you use it justify the extra transmission calibration.

Which setup fits your truck: If the Duramax truck is your daily driver or spends hours on the highway, a 4-inch system with a muffler is the easier setup to live with. If exhaust sound is part of the build, the 5-inch straight option is there. If you tow regularly, you can add the TCM Tune option when configuring the same kit rather than treating it as another Full Delete Kit.

Not the right pick if: you own a 2024-2026 Duramax truck. Those models use the E42 platform and need the newer ECM access route. It's also more package than you need if you already have compatible exhaust and EGR hardware and are only shopping for tuning.

What owners run: A 2018 L5P owner asking about a delete kit and clean tune was looking at the same basic decision: the hardware and tuning have to work as one setup, and the tuning side is a major part of the total cost[4].

Best for: your 2017-2023 Silverado or Sierra 2500HD/3500HD Duramax pickup is still mostly stock and you want the hardware, ECM tuning and exhaust configuration matched before you start taking the Duramax apart.

Best for 2024-2026 - Full E42 DPF/DEF/EGR Delete Kit - From $3,694

Why to buy this one: If you own a 2024, 2025 or 2026 L5P Duramax, this Full DPF/DEF/EGR Delete Kit for 2024-2026 is the correct path for the newer E42 platform. The package combines the emissions-removal hardware, ECM access, programming equipment and vehicle-specific calibration, with prices starting at $3,694.

The important difference is the ECM workflow. The factory E42 ECM must be bench-unlocked before it can be programmed, then the supplied calibration is flashed through OBD II after the controller is reinstalled.

Available power levels are Stock, +35, +70, +125 and +180 HP. Unlike the 2017-2023 E41 package, these aren't traditional SOTF levels. Each setting is a separate calibration, so changing power levels requires reflashing. A Multi-Tune package is available if you want access to all five files.

Hardware choices include a DPF Delete Pipe, 4-inch exhaust or 5-inch exhaust, with muffled versions available for owners who don't want a straight-pipe setup.

Why it stands out

• It's built specifically for the 2024-2026 E42 ECM Duramax platform.
• Available calibrations run from Stock to +180 HP.
• The current product covers 2024, 2025 and 2026 L5P pickups, rather than treating 2026 as an unconfirmed carryover year.
• The ECM and mechanical parts are handled as one year-matched setup.

Which setup fits your truck: For a Duramax truck that works or tows regularly, the lower power files and a 4-inch muffled exhaust make more sense than automatically choosing the loudest exhaust and highest calibration. If you're building around sound or higher output, the larger exhaust and higher files are available without changing to a different Full Delete Kit.

Not the right pick if: your truck is a 2017-2023 L5P Duramax. Those years use E41 electronics and a different tuning workflow. You also shouldn't pay for a Multi-Tune package if you already know you'll stay on one calibration.

What owners run: In 2025, an L5P owner was still asking whether a complete kit existed for the newer platform. The current Dieselino package now lists 2024, 2025 and 2026 compatibility, which closes the model-year gap that owner was asking about.

Best for: your 2024, 2025 or 2026 Duramax Silverado or Sierra 2500HD/3500HD pickup is still stock and you need the E42 ECM work, calibration and physical hardware matched as one package.

An L5P delete is different because the electronics matter just as much as the hardware under the Duramax truck. Your L5P ties the DPF, DOC, SCR/DEF system, EGR hardware and related sensors into the ECM and vehicle network, so you can’t treat it like an older Duramax where the main question was simply which pipe and tuner to buy.

The factory exhaust aftertreatment system includes the DOC, diesel particulate filter, SCR catalyst and DEF/urea system, while the EGR valve and EGR cooler handle a separate part of the emissions strategy. NOx sensors and other monitored components feed information back to the truck. If you remove those parts while the factory calibration still expects them, you can trigger diagnostic codes, warning lights, regen requests, limp mode or a derate condition.

The next difference is the ECM:

2017-2023 L5P Duramax trucks use the E41 ECM family, while 2024+ trucks move to the newer E42 ECM architecture. That isn’t a small model-year update. The controller access, licensing and tuning workflow are different enough that the E41 and E42 packages need to be treated as separate buying paths.

There’s another practical detail owners often miss: L5P CAN bus plugs.

Your Duramax truck’s control modules communicate over the CAN network. When supported emissions-related modules are removed, the rest of the network may still expect those modules to be present. The correct year-specific CAN solution helps prevent the missing-module communication faults owners often describe as “ghost codes.”

That’s why we don’t rank L5P Full Delete Kits by 4-inch versus 5-inch exhaust alone. The model year, ECM and tuning path come first; the pipe size is a configuration choice inside that correct package.

If you want the installation process rather than the buying decision, use our separate guide: How to Delete an L5P Duramax the Right Way.

Yes. Your L5P Duramax model year determines the ECM architecture, controller workflow and several parts of the tuning package, so the correct Full Delete Kit has to be matched to the Duramax before you choose exhaust size or power level. The main split is 2017-2023 E41 versus 2024+ E42, with additional differences inside the earlier E41 years.

2017-2019 L5P Delete Kit

For 2017, 2018 and 2019 L5P Duramax trucks, the main difference is the early E41 ECM workflow. Your calibration is prepared for your truck's VIN and ECM information, with Stock, +50, +75, +100 and +150 HP SOTF levels available. If you want transmission tuning as part of the setup, these years use the optional T87A TCM route with the Allison six-speed. The complete Full Kit currently starts at $3,227.

2020-2023 L5P Delete Kit

For 2020, 2021, 2022 and 2023 Duramax trucks, the ECM is still E41, but the supporting hardware changes for these later model years. The tune is prepared for your truck's VIN and stock file, and CAN bus plugs are included where required to prevent communication faults after the emissions modules are removed. If you add transmission tuning, these trucks use the T93 TCM with the Allison 10L1000.

2024-2026 L5P Delete Kit

For 2024, 2025 and 2026 Duramax trucks, the big change is the E42 ECM. These years use the separate 2024-2026 Full Delete Kit, and the factory ECM has to go through a bench unlock before it can be programmed.

The available calibrations are Stock, +35, +70, +125 and +180 HP. These aren't traditional SOTF files, so changing power levels means reflashing the ECM rather than switching tunes on the fly.

Your model year therefore decides the electronics before it decides the exhaust. Once you know whether your truck needs the early E41, later E41 or E42 path, the rest of the kit becomes much easier to configure correctly.

An L5P full delete kit should cover both sides of the project: the mechanical DPF/DEF/EGR hardware and the correct ECM tuning path for your truck. That’s what separates a real Full Delete Kit from a cheap L5P DPF delete kit made up of only a pipe and a few brackets. Your exact contents change by model year and exhaust option, but the core pieces stay consistent.

DPF/CAT Delete Pipe: includes a 4-inch stainless steel replacement pipe with welded sensor bungs, reinforced flanges, mounting brackets, hangers and the clamps needed for installation. It replaces the factory DPF/CAT section, with straight-pipe or muffled configurations available depending on the selected option.

The L5P EGR delete kit removes the EGR valve/cooler hardware and includes the block-off plate, EGR pipes, coolant-routing fittings, seals and stainless mounting hardware. The standalone 2017-2025 kit currently sells for $297, but it’s already included as part of the complete bundle.

ECM tuning and unlock hardware: the Duramax kit must also match your controller. The 2017-2023 Full Kit includes the appropriate ECU Unlock Tool, custom calibration and SOTF package, while the 2024-2025 E42 package includes its separate unlock route and 8 tuning credits.

CAN bus plugs: where required, the correct communication plugs are included so the truck’s network is configured for the removed emissions hardware.

Clamps, gaskets and mounting hardware: full exhaust configurations include the bolts, clamps and hangers needed for installation, while the EGR side includes its own seals and block-off hardware.

What do owners commonly add? A 4-inch or 5-inch T-409 stainless muffler currently starts at $140, while a FASS Duramax fuel system starts at $677 for owners building beyond the basic delete package. Neither is required to make the Full Duramax Kit complete.

A separate 3.5-inch L5P downpipe is also available as a standalone upgrade for 2017-2026 Duramax trucks.

The right L5P tuner path depends on what you already own. If your Duramax truck is still stock, the Full Delete Kit with the correct ECM hardware and calibration is usually the cleanest route. If you already have the exhaust, EGR hardware or compatible programming interface, a standalone ECU tool or tune package can save you from buying the same parts twice.

Full Kit with ECM tuning: this is the simplest route if you're starting with a stock Duramax truck, because the tuning path is already matched to the hardware you're ordering. You follow the year-specific ECM process, provide the required vehicle information and stock file, then load the custom calibration prepared for your truck. The tradeoff is time: ECM access and tune preparation have to be completed before the truck is ready to run the new setup.

Standalone ECU Unlock / Tuning Tool: this route makes sense if you already have the mechanical parts and only need to handle ECM access and programming. You use the year-specific tool or interface, send the required truck information and stock file, then flash the calibration once it's ready. You're saving money by not buying the hardware twice, but you're responsible for making sure the parts already on the truck match the tune.

Unlocked E41 ECM: this is the route for an owner who wants to keep the original ECM separate instead of modifying it. You install the prepared replacement ECM and complete the required programming around that controller. The tradeoff is availability and the extra setup involved in swapping to a different module.

SOTF Tune Package: this option is for a truck that already has compatible ECM access and programming hardware in place. You load the custom calibration onto an already prepared setup and get the supported SOTF power levels without buying another complete hardware package. The catch is simple: the unlock and compatible interface have to be handled before this option makes sense.

If you’re searching for the best tuner for L5P Duramax, don’t choose by device name alone. Start with your ECM, what hardware you already own and whether you need a complete programming route or only the calibration.

For 2017-2023 trucks, SOTF gives you Stock, +50, +75, +100 and +150 HP choices. If you tow regularly, the tow-oriented level is usually more useful than the highest available power file; maximum horsepower and the best working-truck calibration are not the same thing.

For most L5P Duramax owners, a 4-inch L5P exhaust is the practical choice for daily driving and towing, while a 5-inch system is better suited to owners who deliberately want a deeper, louder exhaust note. The 3.5-inch L5P downpipe is a separate turbo-side component, so it should not be treated as another full exhaust diameter.

You'll usually see three materials used for diesel exhaust and delete pipes: aluminized steel, T-409 stainless and T-304 stainless. Aluminized steel is the cheapest, while T-304 sits at the premium end; for most working trucks, T-409 is the sensible middle ground because it handles heat and corrosion well without the price of T-304. Our current L5P options include aluminized and T-409 construction depending on the system, with the 5-inch exhaust listed in T-409 stainless. Saving money on aluminized steel can be false economy if you drive through salted winters - once corrosion takes over, you're paying for the pipe and the installation work again. Wall thickness matters, but so do the welds, flanges and joints: that's where a poor-fitting system usually starts leaking or whistling.

Sound is where I'd choose based on how you actually drive the truck. A straight-pipe L5P is loud, and if you spend two hours on the interstate with a trailer or your family in the cab, that constant drone can get old quickly; that's why we'd usually put a muffler on a daily-driven or towing setup. If you want the truck to be noticeably louder every time you get into the throttle, the straight configuration makes sense - just choose it deliberately. You can select straight or muffled when ordering the kit, which is easier and cheaper than changing the L5P delete pipe or exhaust configuration after everything is already installed.

Your Allison transmission has its own computer, the TCM, and changing the engine calibration doesn't automatically change the transmission tune. That matters once your L5P is making more power. Hook up a heavy trailer, accelerate onto the highway or pull a long grade, and the transmission is still shifting according to its original factory strategy. That's where you may notice shifts that feel too firm or happen at the wrong time for the new engine output.

The solution is to unlock and tune the TCM separately. For 2017-2019 trucks, Dieselino offers the T87A TCM Unlock Tool; 2020-2023 trucks use the T93 TCM Unlock Tool. Both currently start at $299 and TCM tuning can also be selected as an option with the Full Delete Kit.

If you tow regularly, run larger tires or use the higher power files, TCM tuning is worth considering. If you stay close to stock power and already like how the transmission shifts, you don't need to add it just because the option is available.

A realistic L5P delete cost starts at about $3,227 for a complete 2017-2023 kit or $3,694 for a 2024-2025 E42 kit, while a full project with typical outside-shop labor can reach roughly $4,100-$5,200 before optional TCM work, shipping and taxes. Your total is made up of the Full Delete Kit, any transmission-tuning option and the labor you don’t perform yourself. Where your truck lands in that range depends mainly on the model year, selected configuration and whether you install the hardware yourself.

The $682 hardware-only figure comes from the current $297 EGR kit plus the $385 DPF/CAT Delete Pipe. It’s useful for an owner who already has the correct tuning path, but it isn’t the real cost of starting with a stock L5P Duramax.

For labor planning, Dieselino lists 6-10 hours for the 2024-2025 Full Kit mechanical installation, excluding ECM shipping and unlock time. Using the current $149 median heavy-duty shop labor rate as a market reference puts that labor at roughly $894-$1,490.

That brings a $3,227 2017-2023 Full Kit to roughly $4,121-$4,717 with comparable outside labor. A $3,694 E42 kit lands around $4,588-$5,184 before an optional TCM, shipping or tax.

Your final cost depends mainly on the model year, the options you add and whether you handle the installation yourself or use a shop.

A properly configured deleted L5P can change how the truck delivers power, uses fuel and behaves under sustained load, but there isn’t one honest before-and-after result for every truck. The real L5P delete pros and cons depend on your Duramax model year, calibration, tire size, trailer weight and driving style, so we separate published specifications from owner-reported results.

Power

The 2017-2023 L5P was factory-rated at 445 hp and 910 lb-ft of torque. The updated 2024+ L5P is rated at 470 hp and 975 lb-ft [1].

Dieselino’s 2017-2023 package offers Stock, +50, +75, +100 and +150 HP files. The 2024-2025 E42 package goes up to a listed +180 HP Performance calibration.

Those are package-rated tune levels, not guaranteed wheel-horsepower gains. If you tow regularly, the lower tow-oriented calibration may be more useful than the highest available file.

L5P MPG After Delete

There is no reliable guaranteed L5P MPG after delete figure. Recent owner reports range from no noticeable change to roughly 1-3 MPG while towing and 2-4 MPG in favorable rural driving, with speed and throttle use making a major difference[4].

If you want a meaningful result from your own Duramax, hand-calculate several tanks before and after under similar conditions rather than relying only on the dash display.

EGTs

EGT can change when exhaust restriction and calibration change, especially while towing uphill under sustained load. But trailer weight, tune, road grade, ambient temperature and throttle position all affect the number.

We wouldn’t promise your truck will run “100°F” or “200°F cooler” without controlled before-and-after data. If EGT matters to you, log your own Duramax under comparable load and conditions.

Most L5P delete problems come from mismatched parts, the wrong controller workflow or installation steps being done in the wrong order. Your Duramax usually gives you a clue about what went wrong - codes, limp mode, derate or communication faults - so the best approach is to prevent the mismatch before the Duramax is apart.

Here are the six most common L5P delete problems we see owners run into - and what usually causes them.

1. Wrong ECM path for the model year.
   A 2018 E41 truck and a 2024 E42 truck do not use the same tuning workflow. Ordering by engine name alone can leave you with hardware that fits physically but the wrong controller solution. Avoid it by confirming the year, ECM and VIN before ordering.
2. Mechanical parts installed before the calibration is ready.
   If the factory ECM still expects the DPF, SCR/DEF or EGR system to be present, removing those parts first can trigger warnings, regen requests, limp mode or derate. Avoid it by completing the required tuning preparation before disabling monitored hardware.
3. CAN communication faults.
   Removing supported emissions modules can leave other controllers looking for devices that are no longer on the network. That is where owners often run into persistent communication or “ghost” codes. Avoid it by using the correct year-specific CAN bus plugs or network hardware.
4. Low battery voltage during programming.
   An interrupted ECM flash can turn a routine calibration step into a recovery job. Weak batteries, accessories running or unstable voltage increase that risk. Avoid it by using stable battery support and following the programming procedure exactly.
5. Pickup and Cab & Chassis parts get mixed up.
   An L5P Duramax engine designation does not guarantee identical exhaust routing or hardware fitment. A pickup-specific Full Kit may not physically fit your Cab & Chassis Duramax truck. Avoid it by verifying the chassis type separately from tuning compatibility.
6. The wrong exhaust configuration is chosen.
   A 5-inch straight system may sound great outside the truck but become tiring during long highway towing. Exhaust leaks can also appear if clamps or connections are not seated correctly. Avoid it by choosing the sound level around how you actually use the truck and checking every joint during installation.

1. Confirm your exact model year: Your year determines whether you need the E41 or E42 tuning path and which Full Delete Kit configuration fits.
2. Confirm pickup or Cab & Chassis: An L5P engine does not guarantee identical exhaust routing, so mechanical fitment must match your chassis.
3. Send your VIN when fitment is unclear: This is especially important for 2024-2026 trucks, where controller and hardware compatibility should be confirmed before shipping.
4. Make sure ECM tuning is included or already handled: A delete pipe and EGR hardware alone do not make a complete setup on a stock L5P.
5. Choose your exhaust around how you drive: A 4-inch muffled system suits many daily drivers and tow rigs, while a 5-inch straight setup prioritizes sound.
6. Decide whether you need TCM tuning: Regular towing, larger tires or higher engine power levels make the T87A or T93 option more relevant.
7. Check the rules that apply to your truck and intended use: Off-road or competition labeling does not override federal, state or local emissions requirements.